JP4946349B2 - Planar heating element - Google Patents

Description

  The present invention relates to a sheet heating element used for, for example, an electric floor heating panel, an electric carpet, and the like, and more particularly to a printed form of a sheet heating element resistor formed by printing electrodes and resistors. .

  Conventionally, as shown in FIGS. 4A and 4B, this type of planar heating element 101 is obtained by printing and drying a conductive paste on an electrically insulating base material 2 such as a polyester film. A pair of comb-shaped electrodes 3 obtained and a polymer resistor 4 obtained by printing and drying a polymer resistor ink at a position where power is fed by the pair of comb-shaped electrodes 3 are provided. 3 and polymer resistor 4 are covered and protected (see, for example, Patent Document 1). Specifically, the hot melt resin 5 is applied to the covering material 6 in advance, and the entire surface is thermally bonded to join the base material 2 and the covering material 6 via the hot melt resin 5. Thereby, the comb-shaped electrode 3 and the polymer resistor 4 are isolated from the outside world, air does not enter the inside, and there is air between the comb-shaped electrode 3 and the polymer resistor 4 and the covering material 6. Therefore, there is almost no oxidative deterioration of the comb electrode 3 and the polymer resistor 4 due to oxygen in the air, and long-term reliability is imparted.

  FIG. 5 is a plan view of another conventional planar heating element 102. In order to adjust the resistance value or make the heating temperature uniform, the printing region of the polymer resistor 4 is divided into blocks on the base material 2. FIG. It is formed by printing and drying (see, for example, Patent Document 2). Although not shown in the figure, a covering material previously coated with a hot melt resin 5 is thermally bonded onto the base material 2, the comb electrode 3, and the polymer resistor 4.

  It is difficult to finely control the volume resistivity of the polymer resistor 4, and the demand for comfort in the living space becomes strong. The type of the heating element formed by printing as described above is the surface heating element 102. There are many types like this.

  As the polymer resistor ink forming the polymer resistor 4, a base polymer and a conductive material such as carbon black, metal powder, and graphite are dispersed in a solvent. In particular, a crystalline resin is used as the base polymer. Many of them have PTC characteristics (see, for example, Patent Documents 3 and 4).

  The PTC characteristic is a resistance temperature characteristic in which the resistance value increases as the temperature rises, and when the temperature reaches a certain temperature, the resistance value increases rapidly (takes the acronym for Positive Temperature Coefficient in English, meaning that the resistance has a positive temperature coefficient). The polymer resistor 4 having PTC characteristics can provide a planar heating element having a self-temperature adjusting function.

By using such a sheet heating element 102, for example, an electric floor heating panel as shown in FIG. 6 is obtained (see Patent Document 5). In FIG. 6, 11 is a thin wood plate and 12 is a base material. And the thin wood board 11, the base material 12, and the planar heating element 102 are bonded and integrated with an adhesive or the like. Among these, the configuration of the planar heating element is not explicitly described in Patent Document 4, but the planar heating element 102 having the configuration described in the above-described conventional example can be used sufficiently.
Japanese Patent Laid-Open No. 56-13689 Japanese Utility Model Publication No. 57-186997 JP-A-6-96843 JP-A-8-120182 Japanese Utility Model Publication No. 61-93709

  However, in the configuration of the conventional planar heating element 102, when the base material 2 and the covering material 6 are joined by thermal bonding, the base material 2, the comb-shaped electrode 3, the polymer resistor 4 and the covering material 6 inevitably have residual stress. Since the electric resistance characteristics of the polymer resistor 4 fluctuate due to this residual stress, the adhesive force between the polymer resistor 4 and the hot-melt resin 5 applied to the coating material 6 is usually normal. The materials of the polymer resistor 4 and the hot melt resin 5 are selected so as to be small.

  FIG. 7 is a sectional view of the electric floor heating panel 13 using the planar heating element 102 in FIG. 6 along the aa cross section. The heating of the planar heating element 102 causes the thin wood plate 11 and the base material 12 to expand. However, since the thin wood plate 11 and the base material 12 are different in thickness, wood type, etc., the coefficient of thermal expansion is different, and the electric floor heating panel 13 is warped so as to protrude downward or protrude upward (in FIG. 7). As an example, the case of convex downward is illustrated).

  In this case, as shown in FIG. 8, the thin wood plate 11 tends to be peeled off from the planar heating element 102, and the planar heating element 102 is also bonded to the base material 12. In this case, a peeling force 14 is applied via the hot melt resin 5. And this peeling force 14 becomes strong toward the center part from an edge part with respect to both the length direction of the electric floor heating panel 13, and the width direction.

  As described above, since the adhesive force between the polymer resistor 4 and the hot melt resin 5 is small, the peeling force 14 peels off the polymer resistor 4 and the hot melt resin 5. And the hot melt resin 5 are a balance between the adhesive force and the adhesive force between the comb-shaped electrode 3 and the base material 2.

  In terms of position, the main electrode 3a constituting the comb-shaped electrode 3 is in the vicinity of the end in the electric floor heating panel 13, so that the peeling force 14 is small, and the branch electrode constituting the other comb-shaped electrode 3 is used. Since 3b extends toward the center in the electric floor heating panel 13, a large peeling force 14 is applied.

  That is, if the branch electrode 3b is sufficiently dried and strongly adhered to the base material 2, it peels off between the branch electrode 3b and the hot melt resin 5 by the peeling force 14, and the branch electrode 3b is separated from the base material 2. Remain on. On the other hand, since the polymer resistor 4 also remains in the base material 2, the branch electrode 3b and the polymer resistor 4 are electrically and physically joined to each other, so that power is supplied to the branch electrode 3b and the associated high voltage. The heating of the molecular resistor 4 does not change and the electric floor heating panel 13 can be used as usual. However, if the branch electrode 3b is not sufficiently dried and the adhesive force with the base material 2 is weaker than the adhesive force between the branch electrode 3b and the hot melt resin 5, as shown in FIG. 14 causes the branch electrode 3 b to peel off from the base material 2. On the other hand, since the polymer resistor 4 remains in the base material 2, a tensile force is generated on the branch electrode 3b at the end face of the printed region of the polymer resistor 4, thereby increasing the internal resistance of the branch electrode 3b. When the amount of generated heat changes or is severe, there is a possibility that the branch electrode 3b cracks and breaks, resulting in a problem that heat is not generated.

  The present invention solves the above-described conventional problems, and provides a planar heating element that reliably prevents disconnection of a branch electrode even when a peeling force is generated on the planar heating element due to warpage of an electric floor heating panel. For the purpose.

In order to solve the above problems, a planar heating element of the present invention includes a base material, a comb-shaped electrode composed of a pair of main electrodes and branch electrodes formed by printing on the base material, and the pair of and a the branch electrode substantially perpendicular to the plurality of polymer resistor blocks obtained by dividing formed by printing so as to branch electrode electrically and / or physically bound, said on the branch electrodes polymer Resistors are printed , polymer resistors are printed on the branch electrodes in the polymer resistor non-printing region between the polymer resistor blocks, and the polymer resistor blocks are cross-linked, and the base material The entire surface of the comb electrode and the polymer resistor is coated with a coating material coated with a hot melt adhesive by adhering the hot melt to the polymer resistor .

  Therefore, a polymer resistor is placed on the branch electrode, and it is the polymer resistor that is bonded to the hot melt resin. Therefore, the peeling force causes the peeling between the polymer resistor and the hot melt resin. Since the branch electrode is always present on the base material side like the polymer resistor, disconnection does not occur.

  According to the planar heating element of the present invention, the polymer resistor is also printed and dried on the branch electrode running between the plurality of polymer resistor blocks, and the hot melt resin is bonded to the polymer resistor. Therefore, the peeling force is peeled off between the polymer resistor and the hot melt resin, and the branch electrode remains adhered to the base material like the polymer resistor block, thus preventing the branch electrode from being disconnected. it can.

The first invention is electrically and / or physically coupled to a base material, a comb-shaped electrode composed of a pair of main electrodes and branch electrodes formed by printing on the base material, and a pair of branch electrodes. A plurality of polymer resistor blocks formed by printing so as to be substantially orthogonal to the branch electrodes, the polymer resistors being printed on the branch electrodes, and a polymer between the polymer resistor blocks A polymer resistor is printed on the branch electrode in the resistor non-printing region to cross-link between the polymer resistor blocks, and a hot melt adhesive is applied to the entire surface of the base material, the comb electrode, and the polymer resistor. Is coated with a hot melt bonded to a polymer resistor . As a result, the polymer resistor is also printed and dried on the branch electrode running between the plurality of polymer resistor blocks, and the hot melt resin is adhered to the polymer resistor, so that the peeling force Peeling occurs between the polymer resistor and the hot melt resin, and the branch electrode remains adhered to the base material in the same manner as the polymer resistor block, so that disconnection of the branch electrode can be prevented.

  In the second invention, in particular, the polymer resistor block is printed up to the extension start portion from the main electrode of the branch electrode of the first invention, and both sides of the extension start portion from the main electrode of the branch electrode and the end of the branch electrode are printed. A non-printing region of the polymer resistor is provided between the portion and the opposite main electrode. As a result, even if a large peeling force is applied in the vicinity of the extension start portion from the main electrode of the branch electrode, the hot-melt resin is a polymer resistor printed on the extension start portion from the main electrode of the branch electrode. Since it is bonded, the peeling force peels off between the hot melt resin and the polymer resistor, and the extension start portion of the branch electrode from the main electrode remains adhered to the base material like the polymer resistor. Therefore, disconnection at the extension start portion of the branch electrode from the main electrode can be prevented.

  In addition, if the polymer resistor is printed on the main electrode due to bleeding or printing misalignment during printing, and the electrical connection occurs, the current flows through the shortest distance. It becomes easier for current to flow between the extension start portion from the main electrode and the end portion of the branch electrode opposite to the main electrode and the end portion of the branch electrode opposite to the main electrode. As a result, the polymer resistor generates heat in the vicinity of the main electrode, so that the temperature of the main electrode at that location rises, and when the heat insulating material is placed, the temperature further rises. However, in the present invention, the non-printing region of the polymer resistor is provided on both sides of the branch electrode starting portion from the main electrode and between the terminal end portion of the branch electrode and the main electrode of the opposite polarity, so that the shortest current The passage is blocked and the temperature rise of the main electrode is prevented.

  In the third invention, the polymer resistor is projected from the polymer resistor block to the extension start portion from the main electrode of the branch electrode of the first invention. As a result, even if a large peeling force is applied in the vicinity of the extension start portion from the main electrode of the branch electrode, the hot-melt resin is a polymer resistor printed on the extension start portion from the main electrode of the branch electrode. Since it is bonded, the peeling force peels off between the hot melt resin and the polymer resistor, and the extension start portion of the branch electrode from the main electrode remains adhered to the base material like the polymer resistor. Therefore, disconnection at the extension start portion of the branch electrode from the main electrode can be prevented.

  In addition, the polymer resistor block is printed at a distance that is not electrically coupled to the main electrode, and is printed only on the start of the branch electrode extending from the main electrode. Current flows between the starting part of the main electrode and the terminal part of the branch electrode opposite to the main electrode and the terminal part of the main electrode opposite to the branch electrode, and the polymer resistor generates heat near the main electrode, There is no problem that the temperature of the main electrode at that point rises.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
In FIG. 1, a sheet heating element 1 has a pair of comb-shaped electrodes 3 made of silver paste printed and dried on a base material 2 made of a thin electric insulating film such as a polyester film. The comb-shaped electrode 3 includes a main electrode 3a and a branch electrode 3b, and a polymer resistor 4 made of polymer resistor ink is printed and dried so as to overlap the branch electrode 3b. The comb electrode 3, the polymer resistor 4, and the base material 2 are covered with a coating material 6 made of a thin-walled electrically insulating film such as a polyester film obtained by laminating a hot melt resin 5 mainly composed of a copolyester resin. Are laminated with a laminator or the like.

  The polymer resistor 4 uses a crystalline resin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer or the like as a base polymer, and contains carbon black and various additives. Since these crystalline resins have no affinity with the copolymerized polyester resin, the adhesive force is weak.

  The printed form of the polymer resistor 4 is based on three rows of polymer resistor blocks 4a, 4b, and 4c, and is printed so that the branch electrodes 3b are substantially orthogonal. The polymer resistor 4 is also printed on the branch electrode 3b running in the non-printing region of the polymer resistor 4 between the polymer resistor blocks 4a and 4b and between 4b and 4c. The polymer resistor blocks 4a, 4b and 4c and the polymer resistor 4 on the branch electrode 3b are formed by one printing and drying using one screen printing plate. That is, in other words, the printed shape of the polymer resistor 4 is such that the non-printing region 7a of the rectangular polymer resistor 4 is aligned between the branch electrodes 3b facing each other in the substantially rectangular printed region. It has a side-by-side shape. In the figure, three rows of polymer resistor blocks 4a, 4b, and 4c are shown, but the number of rows, the width dimension, and the like can be changed depending on how the planar heating element 1 is used.

  Further, the non-printing area 7a is originally for adjusting the resistance value or equalizing the heat generation temperature. If the purpose can be achieved, the non-printing area 7a is not limited to a rectangle but may be a circle, an ellipse or the like.

  FIG. 2 is an enlarged plan view of a portion A in FIG. 1, and the polymer resistor block 4a is printed up to the end of the main electrode 3a, and the extension start portion 8 of the branch electrode 3b from the main electrode 3a is shown. Is covered with a polymer resistor block 4a. Further, a non-printing region 7b of the circular polymer resistor 4 is provided on both sides of the extension start portion 8 of the branch electrode 3b, and a rectangular shape is formed between the terminal portion 9 of the branch electrode 3b and the main electrode 3a having the opposite polarity. The non-printing region 7c of the polymer resistor 4 is provided.

  FIG. 3 is an enlarged plan view of a portion B in FIG. 1, and the polymer resistor block 4c is provided with a distance from the main electrode 3a. This is to prevent the polymer resistor 4 from overlapping the main electrode 3a even if the printing is displaced. Then, the protruding printing part 10 of the polymer resistor 4 is superposed on the branch electrode 3b and printed up to the extension start part 8 from the polymer resistor 4c.

  The width of the polymer resistor 4 printed on the branch electrode 3b is not the same as the width of the branch electrode 3b, and the branch electrode 3b covers the branch electrode 3b even if the printing of the polymer resistor 4 is shifted. Printing is larger than the width of.

  Next, the operation and action will be described.

  In FIG. 1, all the branch electrodes 3 b are covered with the polymer resistor 4, and the hot melt resin 5 is bonded to the polymer resistor 4. Therefore, even if the peeling force 14 is generated in the sheet heating element 102 due to the warp of the electric floor heating panel 13 as shown in FIG. 7, the peeling is caused by the peeling between the polymer resistor 4 and the hot melt resin 5. The branch electrode 3b is still adhered to the base material 2. In addition, the polymer resistor 4 is also bonded to the base material 2, and the branch electrode 3b and the polymer resistor 4 do not change in electrical and / or physical state. Therefore, disconnection of the branch electrode 3b can be reliably prevented.

  Further, the non-printing region 7b provided in the vicinity of the extension start portion 8 of the branch electrode 3b is an end of the branch electrode 3b opposite to the extension start portion 8 of the branch electrode 3b, which is one of the shortest paths through which current flows. Since the gap with the portion 9 is blocked, the polymer resistor 4 does not generate heat. Similarly, the non-printing region 7c provided between the terminal portion 9 of the branch electrode 3b and the main electrode 3a having the opposite polarity is the same as the terminal portion 9 of the branch electrode 3b, which is one of the shortest paths through which current flows. Since the main electrode 3a is blocked, the polymer resistor 4 does not generate heat even during this period. Therefore, the temperature rise of the main electrode 3a at this location is prevented.

  As described above, the planar heating element according to the present invention is a comb-shaped electrode that supplies electric power even if peeling force generated by warpage due to thermal expansion difference of wood of the electric floor heating panel is applied to the planar heating element, In particular, the branch electrode does not break, and the heat generated by the polymer resistor can be obtained continuously. Useful.

The top view which shows the structure of the planar heating element in Embodiment 1 of this invention Part A enlarged view of the planar heating element in Embodiment 1 of the present invention. The B section enlarged view of the planar heating element in Embodiment 1 of this invention (A) Top view which shows the structure of the conventional planar heating element (b) xy sectional drawing of the same planar heating element The top view which shows the structure of the other conventional planar heating element. Perspective view of an electric floor heating panel using a conventional sheet heating element Usage aa sectional view of electric floor heating panel Usage sectional view of electric floor heating panel Usage state bb of electric floor heating panel

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar heating element 2 Base material 3 Comb electrode 3a Main electrode 3b Branch electrode 4 Polymer resistor 4a, 4b, 4c Polymer resistor block 5 Hot melt resin 6 Coating material 7a, 7b, 7c Non-printing area 8 Extension Start part 9 Terminal part 10 Projection printing part 11 Wood thin plate 12 Base material 13 Electric floor heating panel

Claims (3)

A base material; a comb-shaped electrode comprising a pair of main electrodes and branch electrodes formed by printing on the base material; and the branch electrodes so as to be electrically and / or physically coupled to the pair of branch electrodes. and a plurality of polymer resistor blocks obtained by dividing formed by printing so as to be substantially perpendicular, a polymer resistor on the branch electrodes of the polymer resistor non-printing area between the polymer resistor block The polymer resistor block is printed and cross-linked, and a coating material in which a hot melt adhesive is applied to the entire surface of the base material, the comb-shaped electrode, and the polymer resistor is coated with the hot melt adhesive. A planar heating element formed by adhering and covering a molecular resistor . The polymer resistor block is printed up to an extension start portion of the branch electrode from the main electrode, and the opposite ends of the branch electrode from the main electrode and the end portions of the branch electrode are opposite to each other. The planar heating element according to claim 1, wherein a non-printing region of the polymer resistor is provided between the main electrode and the main electrode. The planar heating element according to claim 1, wherein the polymer resistor is projected and printed from the polymer resistor block to an extension start portion of the branch electrode from the main electrode.